Air bearing slider with shaped taper

ABSTRACT

An air bearing slider used with a thin film magnetic head is formed with a corner recess and a taper at the leading edge. The taper is disposed between the corner recess and one side of the slider. A central polygon-shaped recess is bounded by pads which are joined by a connecting section. In an alternative embodiment, a recess at the leading edge separates the taper into sections. In another embodiment, a second corner recess is provided at the leading edge and the taper is disposed between the first and second corner recesses. The shaped recesses and tapers improve the flying characteristics of the slider and enhance air bearing stiffness. A single etch process is used to form the recesses and side reliefs of the slider.

This is a division of application Ser. No. 08/797,169 filed Feb. 10,1997.

FIELD OF THE INVENTION

This invention relates to an air bearing slider with a patterned leadingtaper region and configured rails or pads and recesses.

DESCRIPTION OF THE PRIOR ART

Magnetic head assemblies that fly relative to rotating magnetic disksare used extensively in disk drives for recording and reading data. Oneobjective when using a flying head on which at least one magnetictransducer is deposited in a transducing relationship with a magneticrecording disk is to maintain a substantially constant flying heightmeasured between the slider transducer and the disk surface. Also, bymaintaining a constant flying height at a close spacing between thetransducer and the disk surface, it is possible to record shortwavelength or high frequency signals thereby realizing high density andhigh storage capacity data recording.

Air bearing sliders used in disk drives typically have a leading edgewith a taper at the leading edge and a trailing edge at which thin filmtransducers are deposited. Typically, the sliders have tapered portionsat the leading edge and longitudinal rails or pads that extend from theleading edge tapers towards the trailing edge. The tapers may be shapedand of such length as to provide fast pressure buildup during takeoff ofthe slider from a resting position to flying attitudes relative to thedisk. The dimensions and shapes of the tapers and rails are instrumentalin determining the flying characteristics of the head. The rail designdetermines the pressure generated at the air bearing surface of theslider. In effect, the pressure distribution underneath the sliderdetermines the flying characteristics, including flying height, pitchand roll of the head relative to a rotating magnetic disk. Othercharacteristics that are affected by the configuration of the airbearing surface of a slider are takeoff velocity, air bearing stiffnessand track seek performance. It is highly desirable to fly the slider ata substantially constant flying height close to the disk surface, whilesimultaneously providing fast takeoff and good track seekcharacteristics that can affect drive reliability. These objectivesshould be attained with simplified, low cost manufacturing processes.

SUMMARY OF THE INVENTION

An object of this invention is to provide an air bearing slider thataffords a substantially constant flying height.

Another object is to provide an air bearing slider with low takeoffvelocity and minimum track seek flying height variation.

Another object is to provide an air bearing slider that has enhanced airbearing stiffness which results in a tighter flying height distributiondue to manufacturing tolerance.

According to this invention, the air bearing surface of an air bearingslider is formed with configured taper and rails or pads that define ashaped central recess. In one embodiment of the invention, a continuoustaper region is formed at the leading edge of the slider between oneside of the slider and a corner recess region. In an alternativeembodiment, leading edge taper portions separated by a recessed area areprovided, with a corner recess region adjacent to one of the taperportions. In a third embodiment of the invention, a leading edge taperis located between two corner recess regions. In each embodiment, apolygon type central recess is defined between the connecting rails orpads of the air bearing surface. Each recess is etched to the same depthin a single process step, by reactive ion etching or ion milling forexample.

BRIEF DESCRIPTION OF THE DRAWING

The invention will be described in greater detail with reference to thedrawing in which:

FIG. 1 is a top view depicting an air bearing surface of an air bearingslider configured in accordance with this invention;

FIG. 2 is a top view of an alternative embodiment of the invention; and

FIG. 3 is a top view of a third embodiment of the invention.

Similar numerals refer to similar elements in the drawing. It should beunderstood that the sizes of the different components in the figures arenot necessarily to scale and are shown for visual clarity and for thepurpose of explanation.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be described with reference to a nanoslider, whichhas dimensions that are about 50% of a conventional slider. A nanoslideris typicaly 0.080 inch long, 0.063 inch wide and 0.017 inch high. Theinvention is also applicable to other size sliders, such as picosliderswhich have dimensions about 30% of a conventional slider.

With reference to FIG. 1, an air bearing slider is formed with two pads10, 12 with a connecting section 9. The pads 10, 12 and connectingsection 9 define a polygon-type central recess 15 which is substantiallycentered about the longitudinal axis of the slider, which axis extendsbetween the leading edge 11 and the trailing edge 13 of the slider. Therecess 15 extends from the connecting section 9 to the trailing edge 13of the slider.

As illustrated in FIG. 1, one configuration of the air bearing surface(ABS) of the slider of this invention is made with a corner recessregion 32, which is substantially triangular in shape. The angle ∝formed between the side of the slider and the hypotenuse of the triangleof the corner recess region is in the range of about 30-60 degrees. Atone side of the slider, a side relief 17 extends fully between theleading edge 11 and trailing edge 13, whereas at the other side of theslider, a side relief 19 extends from the trailing edge 13 to theangular side or hypotenuse of the triangular recess 32.

The pad 10 is formed with a trapezoidal region 18 and a trapezoidalregion 26 with a narrowed rectangular region 22 between the trapezoidalregions 18 and 26, and between a side relief 17 and the recess 15.Following the trapezoidal region 18, a rectangular area 14 is formed atthe trailing end of the slider between the recess 15 and the trapezoidalregion 18. At the other side of the slider and at the opposite portionof the recess 15, the pad 12 is formed with a rectangular area 16corresponding to the rectangular area 14; a trapezoidal region 20corresponding to the trapezoidal region 18; a narrowed rectangularregion 24 corresponding to the rectangular region 22; and a trapezoidalregion 28 opposite to trapezoidal region 26. The widths of the opposingregions typically have different dimensions. Also the trapezoidal region28 differs in shape from the opposing region 26 because the cornerrecess 32 cuts across region 28.

The pads 10, 12 and connecting section 9 provide superambient airpressure regions on the air bearing surface of the slider, whereas therecess 15 and recess 32 produce opposing subambient pressure regions.

One feature of the invention, which enables enhanced flying performanceof the slider with low takeoff velocity, is a configured taper 30 thatis disposed at the leading edge of the slider between one portion of theangled side or hypotenuse of the recess 32 and the side relief 17, asshown in FIG. 1. The taper 30 is trapezoidal wherein the side of thetaper contiguous with the hypotenuse of the recess 32 is angled. Theangle α between the side relief 19 and the hypotenuse is in the range of30-60 degrees approximately.

In a specific implementation of the invention, the widths of therectangular regions 22 and 24 measured between the side reliefs and therecess 15 were about 0.008 inch respectively, and the widths of therectangular areas 14 and 16 were about 0.015 inch respectively. Thedimension of the taper 30 measured from the leading edge 11 to theconnecting section 9 is about 0.008 inch and the overall length of thetaper 9 from the side relief 17 to the recess 32 is about 0.040 inch.The dimension of the connecting section 9 measured from the taper 30 tothe recess 15 is about 0.010 inch.

In an alternative embodiment, as illustrated in FIG. 2, the leading edgetaper 30 of FIG. 1 is divided by a recess 42 that separates arectangular region 40 and a trapezoidal region 38. A part of the recess42 extends into the connecting section 9. The additional recessed areaserves to bring the leading edge of the slider closer to the surface ofthe rotating magnetic storage disk during operation of a disk drive sothat the pitch of the slider relative to the disk is optimized.

FIG. 3 illustrates another embodiment of the invention whereintrapezoidal corner recesses 44 and 50 are disposed about the sides of acentral taper 48. The corner recesses are made with different areas. Thesection 46 connecting the pads 10 and 12 is defined by the central taper48, the angled sides of the trapezoidal recesses 44 and 50, and portionsof the inner sides of the recesses 44 and 50. The angles β₁ and β₂between the angled sides of the recesses 44 and 50 and the side reliefs17 and 19 are preferably about 15-45 degrees. This ABS configurationallows better control of flying attitudes of the slider.

The recesses in each embodiment as well as the side reliefs are etchedto the same depth, which is about 2-5 microns. Etching is effectuatedwith a single etch step using available techniques such as ion millingor reactive ion etching. The leading edge tapers are mechanically lappedso that the resulting pressure distribution across the rails and the ABScan be controlled. Each slider has one or more thin film transducers atthe trailing end, as is well known in the art.

The advantages of this invention are constant flying height, fasttakeoff with low takeoff velocity, improved air bearing stiffness andgood track seek performance.

It should be understood that the geometry, dimensions and parametersdescribed above may be modified within the scope of the invention. Forexample, the widths and lengths of the rails may be modified dependingupon the disk drive operating characteristics. Also the etch depths ofthe recesses may differ for different applications. The rails and thecentral recess may vary in proportions depending upon the slider size.Other modifications may be made when implementing the invention for aparticular environment. While the invention has been described inrelation to a nano-sized slider, it should be understood that thepresent concept may be applied to other sliders of different sizes.

What is claimed is:
 1. An air bearing slider formed with an air bearingsurface having a leading edge and a trailing edge with substantiallyparallel first and second slider sides extending from said leading edgeto said trailing edge, said slider having a central longitudinal axisbetween said edges, comprising:at least one thin film magnetictransducer disposed at the trailing edge of said slider for transducingaction with a magnetic disk; a taper disposed partially at said leadingedge including a rectangular recess disposed at said leading edge, saidrectangular recess dividing said taper into separated first and secondsections, said first section being substantially rectangular and saidsecond section having an angled side; first and second air bearingnonrectangular pads asymmetric relative to said central longitudinalaxis, said pads extending to said trailing edge and having an airbearing connecting section therebetween; a central recess disposedbetween said air bearing pads, said central recess being asymmetricrelative to said central longitudinal axis and formed with a polygonshaped portion and a rectangular recess portion, said rectangular shapedportion disposed between said polygon recess portion and said trailingedge, said polygon shaped recess portion disposed between saidconnecting section and said rectangular recess portion; and a triangularcorner recess formed at a corner of said slider, said triangular cornerrecess having a first side contiguous with said leading edge and asecond side contiguous with said second slider side and a third sidecontiguous with said connecting section, said second bearing pad, andsaid angled side; first and second side reliefs formed respectivelyalong said first and second side of said slider, said second side recessbeing contiguous with said angled side.
 2. An air bearing slider as inclaim 1, wherein said recesses and said side reliefs are etched to thesame depth.
 3. An air bearing slider as in claim 2, wherein said etcheddepth is about 2 to 5 microns.
 4. An air bearing slider as in claim 1,wherein said taper is continuous from said first side relief to saidtriangular first corner recess.
 5. An air bearing slider as in claim 1,wherein said triangular corner recess is patterned as a hypotenuseextending between ends of said sides of said triangular corner recess,said hypotenuse being disposed at an angle between 30-60 degreesrelative to the sides of the slider.